<template>
    <div class="goods">
      <div class="menu-wrapper" ref="menuWrapper">
        <ul>
          <li v-for="(item, index) in goods" class="menu-item menu-list-hook" :class="{'current':currentIndex===index}" @click="selectMenu(index,$event)">
            <span class="text border-1px">
              <span v-show="item.type>0" class="icon" :class="classMap[item.type]"></span>{{item.name}}
            </span>
          </li>
        </ul>
      </div>
      <div class="foods-wrapper" ref="foodsWrapper">
        <ul>
          <li v-for="item in goods" class="food-list food-list-hook">
            <h1 class="title">{{item.name}}</h1>
            <ul>
              <li v-for="food in item.foods" class="food-item border-1px">
                <div class="icon">
                  <img width="57" height="57" :src="food.icon" :alt="food.name">
                </div>
                <div class="content">
                  <h2 class="name">{{food.name}}</h2>
                  <p class="desc">{{food.description}}</p>
                  <div class="extra">
                    <span class="count">月售{{food.sellCount}}份</span><span>好评率{{food.rating}}%</span>
                  </div>
                  <div class="price">
                    <span class="now">￥{{food.price}}</span><span class="old" v-show="food.oldPrice">￥{{food.oldPrice}}</span>
                  </div>
                </div>
              </li>
            </ul>
          </li>
        </ul>
      </div>
      <shopcart :deliveryPrice="seller.deliveryPrice" :minPrice="seller.minPrice"></shopcart>
    </div>

</template>
<script type=text/ecmascript-6>
import BScroll from 'better-scroll';
import shopcart from 'components/shopcart/shopcart';

export default {
  props: {
    seller: {
      type: Object
    }
  },
  data () {
    return {
      goods: [],
      listHeight: [],
      scrollY: 0
    };
  },
  created () {
    this.classMap = ['decrease', 'discount', 'special', 'invoice', 'guarantee'];
    this.$http.get('./api/goods').then(response => {
      response = response.body;
      if (response.errno === 0) {
        this.goods = response.data;
        this.$nextTick(() => {
          this._initScroll();
          this._calculatHeight();
        });
      }
    });
  },
  computed: {
    currentIndex () {
      for (let i = 0; i < this.listHeight.length; i++) {
        let height1 = this.listHeight[i];
        let height2 = this.listHeight[i + 1];
        if (!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
          return i;
        }
      }
      return 0;
    }
  },
  methods: {
    selectMenu (index, event) {
      // bug 在PC页面时 点击会有原生的事件和BScroll派发的点击事件，会有2次事件，解决如下
      if (!event._constructed) {
        return;
      }
      let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook');
      let el = foodList[index];
      this.foodsScroll.scrollToElement(el, 300);
    },
    _initScroll () {
      // v-ref、v-el 弃用 统一使用ref属性为元素或组件添加标记，然后通过this.$refs获取
      this.menuScroll = new BScroll(this.$refs.menuWrapper, {
        click: true // 派发了一个点击事件
      });

      this.foodsScroll = new BScroll(this.$refs.foodsWrapper, {
        probeType: 3 // 设置 probeType: 3 实时监测滚动位置
      });
      this.foodsScroll.on('scroll', pos => {
        this.scrollY = Math.abs(Math.round(pos.y));
        let MenuList = this.$refs.menuWrapper.getElementsByClassName('menu-list-hook');
        if (this.currentIndex > Math.abs(Math.round(MenuList.length / 2)) || this.currentIndex < 1) {
          this.menuScroll.scrollToElement(MenuList[this.currentIndex], 300);
        }
      });
    },
    _calculatHeight () {
      let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook');
      let height = 0;
      this.listHeight.push(height);
      for (let i = 0; i < foodList.length; i++) {
        let item = foodList[i];
        height += item.clientHeight;
        this.listHeight.push(height);
      }
    }
  },
  components: {
    shopcart
  }
};
</script>
<style lang="stylus" scoped rel="stylesheet/stylus">
  @import "../../common/stylus/mixin"
  .goods
    display: flex
    position: absolute
    top: 174px
    bottom: 46px
    width: 100%
    overflow: hidden
    .menu-wrapper
      flex: 0 0 80px
      width: 80px
      background: #f3f5f7
      .menu-item
        display: table
        height: 54px
        width: 56px
        padding: 0 12px
        line-height: 14px
        &.current
          position: relative
          z-index: 10px
          margin-top: -1px
          background: #fff
          font-weight: 700
          .text
            border-none()
        .icon
          display: inline-block
          vertical-align: top
          width: 12px
          height: 12px
          margin-right: 2px
          background-size: 12px 12px
          background-repeat: no-repeat
          &.decrease
            bg-image('decrease_3')
          &.discount
            bg-image('discount_3')
          &.special
            bg-image('special_3')
          &.invoice
            bg-image('invoice_3')
          &.guarantee
            bg-image('guarantee_3')
        .text
          display: table-cell
          width: 56px
          vertical-align: middle
          border-1px(rgba(7,17,27,0.1))
          font-size: 12px
    .foods-wrapper
      flex: 1px
      .title
        padding-left: 14px
        height: 26px
        line-height: 26px
        border-left: 2px solid #d9dde1
        font-size: 12px
        color: rgb(147,153,159)
        background: #f3f5f7
      .food-item
        display: flex
        margin: 18px 18px 0
        padding-bottom: 18px
        border-1px(rgba(7,17,27,0.1))
        &:last-child
          border-none()
          margin-bottom: 0
        .icon
          flex: 0 0 57px
          margin-right: 10px
        .content
          flex: 1
          .name
            margin: 2px 0 8px 0
            height: 14px
            line-height: 14px
            font-size: 14px
            color: rgb(7,17,27)
          .desc ,.extra
            line-height: 10px
            font-size: 10px
            color: rgb(147,153,159)
          .desc
            line-height: 12px
            margin-bottom: 8px
          .extra
            .count
              margin-right: 12px
          .price
            font-weight: 700
            line-height: 24px
            .now
              margin-right: 8px
              font-size: 14px
              color: rgb(240,20,20)
            .old
              text-decoration: line-through
              font-size: 10px
              color: rgb(147,153,159)
</style>
